Apparatus for making sinuous bends in long workpieces



2 Sheets-Sheet 1 June 28, 1949. A. w. PAYNE APPARATUS FOR KING SINUOUSBENDS IN LONG WORKPIECBS Filed lay B, 1947 June 28, 1949- w, PAYNE2,474,276

APPARATUS FOR MAKING smuous nmms IN LONG WORKPIECES Filfid m 8, 1947 251166128411691. 2

INVEN TOR.

Arthur M. Payne A T7ORNE Y5.

Patented June 28, 1949 APPARATUS FOR MAKING SINUOUS BENDS IN LONGWORKPIECES Arthur W. Payne, Detroit, Mich, assignor to Bundy TubingCompany, Detroit, Mich, a corporation of Michigan Application May 8,1947, Serial No. 746,706

11 Claims. 1

This invention relates to an apparatus for forming long work pieces,such as a tube, into coils of serpentine shape having a series ofreverse bends.

When an elongated piece of stock, such as a tube, is formed into aserpentine coil by the successive making of reverse bends therein, aproblem is immediately encountered in the handling of the work. In someoperations some of the stock is required to be swung through the angleof the bend relative to other portions of the stock and since the stock,in its initial form is quite long, it is usually the practice to swingthe formed portions of the coil relative to the straight run of stock.As the coil builds up in size, this manipulation of the coil becomesincreasingly diflicult. Some rather involved mechanical devices havebeen made to perform this work.

One of the objects of the present invention is to provide an apparatusfor making serpentine coils of a simplified nature wherein a minimum ofmanipulating movements of the stock is required during the bendingoperations. To this end, the invention aims to provide an apparatuswherein two reverse bends are simultaneously made and wherein the formedportions of the coil remain substantially at rest during the bendingoperations with the stock moving substantially only lengthwise in orderto provide the necessary length of tube required to form the runs andbends of the coil.

Other objects will become apparent as the following detailed descriptionis considered in conjunction with the accompanying drawings wherein oneapparatus for carrying out the invention is disclosed:

Fig. 1 is a general side elevational view of an apparatus constructed inaccordance with the invention showing several positions of an op eratingpart in dotted lines.

Fig. 2 is a top plan view showing the support or table and some of theoperating parts.

Fig. 3 is a sectional view taken substantially on line 3--3 of Fig. 1showing a clamp and bending arbor.

Fig. 4 is a sectional view taken substantially on line 4-4 of Fig. 1showing the yieldable mounting of a bending arbor.

Fig. 5 is a small diagrammatic view illustrating the arrangement 01 theapparatus.

Fig. 6 is a view illustrating a modified form of arbor.

Fig. '1 is an end view of the modified form of arbor.

The apparatus advantageously comprises a suitable support or tablehaving a top portion l and supporting legs 2, while other worksupporting elements, as indicated at 3, may project from the table anyrequisite length for carrying the elongated stock, such as the tube,illustrated at T.

Mounted on the support is a post or anchoring member I. Adjacent thepost I, and positioned above the same is a cam element 8 provided withan inclined or cammed surface 9 while an ad justable stop Ill is alsolocated on the table adjacent the post I. A fixed arbor i2 is mounted onthe support in a position spaced from the post 1 distances in twodirections depending upon the size of coil made. A supplemental supportI3 is provided and it may be adjacent the arbor l2 as shown.

Mounted on the table is a swinging arm l5, and this arm is mounted toswing about a pivot on an axis fixed relative to the arbor l2. Thepivotal mounting for the arm I5 is illustrated at ii, the same being inthe form of a stub shaft in a bearing IT. This shaft extends through thebearing, and on its end opposite the arm I5, is a counterweighted arm l8for balancing purposes. In the normal rest position, the arm l5 may besupported by an adjustable stop 20. In a simple mechanism the arm I5 maybe manipulated by hand and for this purpose it is provided with a handle2| connected thereto by an arm 22.

The arm l5 carries a bending arbor 25, and this arbor is slidablymounted in the arm. To this end, there is a slide block 25 slidablymounted in an aperture 21 in the arm for which purpose the blockcomprises a. plate portion 26a attached to the portion 28, as by screws28 so that the two portions overlap opposite sides of the arm and theblock is thus retained in position. As shown in Fig. 4, the arbor 25 hasa stud 3| which extends through the block 26-2611. and is provided onits opposite end with a roller 32. The stud 3i also holds a plate 30 inpivotally mounted position on the block.

A spring structure, which may embody one or more coil springs 35, hasone end mounted in a recess 36 in the arm while its other and acts uponthe block 26 to urge it to the right as Figs. 1 and 4 are viewed,normally against an adjustable stop 31.

The plate 30 carries a clamp structure for clamping the stock. Thisclamp structure, as shown in Figs. 1 and 3, includes a fixed clampingblock 40 positioned immediately adjacent the arbor 25, but in advancethereof, and a movable clamping block it slidably mounted in a guide 3l2 and which is arranged to be acted upon by a cam or eccentric 43provided with an operating handle 44.

The apparatus may be employed to bend a single piece of stock or it maybe used to bend a plurality oi pieces of stock red to the machinesimultaneously. As illustrated in Figs. '2 and 3, two pieces of stock inthe i'orm or tube are disposed in the machine. There is a tail piece IIin the form of a long rod or bar which is attached to the plate 28 andit extends from the machine in the direction from which the stock issupplied and is guided by devices, such as rollers 48 and 49, in thesupport 3. As shown in Fig. 5, the support 3 is removed quite a distancefrom the work table. This bar, as will presently be seen, maintains theposition of the plate 26 and takes the load oil the stock during theswinging action oi the arm II.

The arbors i2, and 25 are shown with smooth surfaces. However, groovedarbors may be used as shown in Figs. 6 and 7. The modified arbor 50 isshown for use with two pieces or stock, and is fashioned with a groove8i and a groove 52. The side portions of the grooves are cut away at oneor more points thus providing flats 53. The flattened ofi portion doesnot extend inwardly beyond the bottom of the grooves but merely removesthe side portions thereof and this permits removal or the formed tube aswill presently be seen.

In the operation or the machine, the several parts are normally in thefull-line position shown in Fig. 1. At this time, the stock T may beadvanced into the machine. It is threaded between the clamp elements Iand 4|, passed over the arbor 25, under the arbor I2, and beyond thepost I. To make the first bend at 1!, around the post I, the operatormay merely bend the stock around the post by hand and may then place theend of the stock over the supplementary support l3 so that the stock isnow held securely in position. The post I is of a size as to provide abend which may be identical to bends formed by the mandrels. Making surethat the bend y is snug against the post 1, the stock is now clamped bymanipulation of the cam 43. With the stock thus located and clamped inthe machine, the handle is grasped and the arm I is swung on its rpivotiii in a counter-clockwise direction as Fig. 1 is viewed.

The resultant action is that of making two bends simultaneously. As thearm I5 is so rocked on its axis the stock is bent around the arbor I! asindicated. Also the stock is bent around the arbor 25 as indicated.Inasmuch as the stock is clamped in position so that there is nolengthwise movement or feeding action of the stock during the bendingoperation. the length of the stock between the center 01' the arbor l2and the center oi! the arbor 25 must be such as to accommodate thelength of stock required in two bends and two runs. By that we mean twoof the bends y in the serpentine form with two adjacent runs a: (Fig.1).

The operation at forming a bend around the arbor I2 is easily understoodas the stock is merely wrapped around the same. As the arm is is swungon its axis, any fixed part of the arm swings on a true radius about theaxis of the pivotal mounting IS. The curve z represents this function:the curve a is an are around the pivot I! on the radius of the center oithe arbor 25 when the arm I5 and arbor 25 are in the rest or startingposition shown in Fig. 1. Howwhich time the roller 32 engages ever, asthe swinging progresses through the dotted line positions shown. theposition of the arbor 25 and clamp must change due to the fact that someof the lineal extent of the tube between the arbor I! and the clamp 40-is taken up in the bends. Accordingly. as the bending operationprogresses, the block 28 is shifted in the slot I! against the action ofthe spring 35 as some 01' the stock is taken up in the wrapping action.Accordingly. the arbor 2| and the clam describe a form of involute curve2'. This may be a compound invoiute curve generated by wrapping thestock about the two arbors l2 and It. The action keeps the stock taut.The plate It rocks on the axis or stud II of the arbor 2B in this actionwith the result that the clamp stays in line with the length of thestock which is clamped thereby.

As the arm it reaches the extreme position as shown to the left, as Fig.l is viewed, the two bends around the arbor l2 and the arbor 25 arecompleted and it is now necessary to remove the bends from the others.This is accomplished by pushing the arm in a downward direction at theinclined surface 9. This pushes the block 26 relative to the arm I 5against the action of the spring 15 toward the arbor I2 to therebyshorten the center to center distance between the arbors so that the twobends may he slipped oi! the arbors. This is the purpose for providingthe flats It on the modified arbor structures. shown in Figs. 5 and 6.The clamp is now released, the bends slipped oil the arbors, and thecoil dropped downwardly so that the bend, which has Just been formedabout the arbor 2!, may be placed over the post I and the run of tubeimmediately under the post hooked over the supplemental support IS. Thearm is now swung clockwise to the full line position shown in Fig. 1,the stock again placed between the clamps. under the arbor l2 and overthe arbor 2i and after the claim) has been applied the arm is swungcounter-clockwise again to make two more bends. This completes one fullcycle, and it will be seen how the formed serpentine coil growsdownwardly, as indicated by the dotted lines shown in Fig. 1.

As will be appreciated by considering Fig. 1. the long length 01' stockis elevated from its support and has imparted thereto a swinging actionas the arm I! is oscillated. In this action, the plate 30 and the clamposcillate about the axis of the stud It and some forces must beovercome. This is the pu po e of the bar or rod ll which is attached tothe plate 30. This bar, as shown in Fig. 5, is of considerable lengthand the stock and bar move together in this action. The bar takeswhatever load there is in connection with the swinging oi the plate 3|]and the clamp, thus relieving the long length or stock of these forces.

The post I, as will be appreciated, performs no bending function in theoperation or the machine other than the first bend which is manuallymade as above described, but is used as a convenient anchor. In otherwords, the stock must bt anchored on the down stream side oi the arborII and since, after the first operation, a bend is available to:anchoring purposes, such bend is merely placed over the post I with theimmediate underlying run disposed on the supplemental support II. Thisanchors the tube and prevents movement or the tube under the action ofthe spring II. The center to center distance between the arbor l2 andthe arbor 25. as above mentioned, is progressively diminished during thebending operation as determined by the take-up in the stock incident tothe stock being wrapped about the arbors. To provide a nlcety of action,the axis of the pivotal mounting It must be so located that all portionsof the involute curve .2 lies within the arcuate curve .1, except in thefullline osition shown in Fig. 1 where the two curves may intersect. Onefactor in the location of the axis of the mounting ii is the radius ofthe bends formed. Inasmuch as the stock is supplied to the apparatus,from the right hand side as Fig. 1 is viewed, the anchoring post I maybe considered as being downstream from the fixed arbor i2 and the clamptil-ll may be considered applicable to the stock upstream from the arbor25. Such terminology is used in the claims appended hereto.

I claim:

1. An apparatus for shaping stock of elongated form, such as tube, intocoils of serpentine form having a succession of reverse bends,comprising a fixed arbor, a movable member mounted to move about thefixed arbor, a yieldably mounted arbor on said member, means foranchoring the stock on one side of the fixed arbor, a clamp on saidmember for clamping the stock on the side of the yieidably mounted arboropposite the fixed arbor, said clamp being yieldably mounted foryieldabie shift in unison with the yieldably mounted arbor, and meansfor moving said member about the fixed arbor to bend the stock aroundthe said two arbors with the arbor on the said member and the clampshifting yieldably on the member to accommodate the take-up in the stockincident to the wrapping of the stock around the arbors.

2. An apparatus for shaping stock of elongated form, such as tube, intocoils of serpentine form having a succession of reverse bends,comprising a fixed arbor, a swinging member, a pivot for the swingingmember, an arbor on the swinging member, a clamp on the swinging member,means yieldably mounting the second mentioned arbor and the clamp on theswinging member, means for anchoring the stock on one side of the fixedarbor, said clam being applicable to the stock on the side of the secondmentioned arbor which is opposite that of the fixed arbor, and means forswinging the member on its pivot to bend the stock about both the saidarbors,

3. An apparatus for shaping stock of elongated form, such as tube, intocoils of serpentine form having a succession of reverse bends,comprising a, fixed arbor, a swinging member, a pivot for the swingingmember, an arbor on the swinging member, a clamp on the swinging member,means yieldabiy mounting the second mentioned arbor and the clamp on theswinging member, means for anchoring the stock on one side of the fixedarbor, said clamp being applicable to the stock on the side of thesecond mentioned arbor which is opposite that of the fixed arbor, andmeans for swinging the member on its pivot to bend the stock about boththe said arbors, the pivot for said swinging member being so locatedrelative to the axis of the fixed arbor that the take-up in the stock,as it is formed about the arbors, shifts the yieldabie arbor and clampon said swinging member.

4. An apparatus for shaping stock of elongated form, such as tube, twocoils oi serpentine form having a succession of reverse bends,comprising a fixed arbor, a swinging member, a pivot for the swingingmember, an arbor on the swin ing member, a clamp on the swinging member,means yieldably mounting the second mentioned arbor and the clamp on theswinging member, means for anchoring the stock on one side of the fixedarbor, said clamp being applicable to the stock on the side of thesecond mentioned arbor which is opposite that of the fixed arbor, andmeans for swinging the member on its pivot to bend the stock about boththe said arbors, the pivot for said swinging member being so locatedrelative to the axis of the fixed arbor that the take-up in the stock,as it is formed about the arbors, shifts the yieldabie arbor and clampon said swinging member in a form of involute curve, all portions ofwhich lie within a true are described by a point on said member which isconcentric with the center oi' the yieldably mounted arbor beforemovement of the said member.

5. An apparatus for shaping stock of elongated form, such as tube, intocoils of serpentine form having a succession of reverse bends,comprising a fixed arbor, an arm pivotally mounted on an axis adjacentthe arbor, a support slidably and rockably carried by the arm, yieldabiemeans acting upon the support, an arbor carried by said support, a clampcarried by said support, said arbors adapted to have a substantiallystraight run of stock positioned adjacent and substantially tangentthereto, means for anchoring the stock on one side of the fixed arbor,the clamp being applicable to the stock adjacent the arbor on saidsupport and on the side thereof opposite from the fixed arbor, means forswinging said arm about its pivot to cause the stock to be bent aboutboth of said arbors, said yieldabie means affording movement of thesupport on said arm to accommodate for the take up of stock as the sameis wrapped around the arbors, said support rocking on its mountingwhereby the clamp remains in substantial alignment with the stock heldthereby.

6. An apparatus for shaping stock of elongated form, such as tube, intocoils of serpentine form having a succession of reverse bends,comprising a fixed arbor, an arm pivotally mounted on an axis adjacentthe arbor, a support slidably carried by the arm, yieldabie means actingupon the support, an arbor carried by said support, a clamp carried bysaid support, said arbors adapted to have a substantially straight runof stock positioned adjacent and substantially tangent thereto, meansfor anchoring the stock on one side of the fixed arbor, the clamp beingapplicable to the stock adjacent the arbor on said support and on theside thereof opposite from the fixed arbor, means for swinging said armabout its pivot to cause the stock to be bent about both of said arbors,said yieldabie means affording movement of the support on said arm toaccommodate for the take up oi. stock as the same is wrapped around thearbors, said clamp being rockable whereby the clamp remains insubstantial alignment with the stock held thereby.

7. An apparatus for shaping stock of elongated form, such as tube, intocoils of serpentine form having a succession of reverse bends,comprising a fixed arbor, an arm pivotally mounted on an axis adjacentthe arbor, a support slidably carried by the arm, yieldable means actingupon the support, an arbor carried by said support, a clamp carried bysaid support, said arbors adapted to have a substantialLv straight runof stock positioned adjacent and substantially tangent thereto, meansfor anchoring the stock on one side of the fixed plicable to the stockafiording movement of the support on said arm to accommodate for thetake up of stock as the same is wrapped around the arbors, said clampbeing rockable whereby the clamp remains in substantial alignment withthe stock held thereby, the pivotal mounting of said arm being sodisposed relative to the fixed arbor that the take up in the tube causesthe arbor on the arm to describe a form of involute curve substantiallyall portions of which are within a true are described on the radius ofthe arbor on the arm prior to the swinging movement of the arm.

8. An apparatus for shaping stock of elongated form, such as tube, intocoils of serpentine form having a succession of reverse bends,comprising a fixed arbor, an arm, means pivotally mounting the armadjacent the fixed arbor, an arbor on the arm, a clamp on the arm, meansyieldably mounting the arbor and clamp for shift of the same relative tothe arm, said arbors arranged so that a substantially straight piece 01'stock may be placed adjacent the same. means for anchoring the stockdownstream from the fixed arbor, the clamp being applicable to the stockupstream from the yieldable arbor, means for swinging the arm about itspivot to cause the stock to be wrapped about the two arbors with theyieldable means providing for shift of the arbor on the arm toaccommodate for the take up of the stock as the same is wrapped aroundthe arbors, and means active upon the arbor on the arm substantially atthe end of the swinging movement to shift the same toward the fixedarbor to thereby loosen the arbors in the bends for removal of the bentportions therefrom.

9. An apparatus for shaping stock of elongated form, such as tube, intocoils of serpentine form having a succession of reverse bends,comprising a fixed arbor, an arm, means pivotally mounting the armadjacent the fixed arbor, a stop upon which the arm may rest, a supportslidably and rotatably mounted on the arm, yieldable means for yieldablyresisting sliding movement of the support, an arbor carried by thesupport, a clamp carried by the support, the two arbors being so relatedthat a substantially straight length of stock may be positioned adjacentthe same with the arbors on opposite sides thereof, means for anchoringthe stock downstream from the fixed arbor, the clamp being applicable tothe stock upstream from the arbor on the arm, means fr swinging the armto cause the stock to be bent about the two arbors with the supportshifting against the yieldable means to accommodate for the take up ofstock as it is bent about the arbors, and means active upon the supportsubstantially at the end of the swinging movement of the arm to shiftthe support on the arm relative to the fixed arbor to thereby loosen theformed bends on the arbors so that the same may be removed therefrom.

10. An apparatus for shaping stock of elongated form, such as tube, intocoils oi serpentine form having a succession of reverse bends,comprising a fixed arbor, an arm, means pivotally mounting the armadjacent the fixed arbor, a stop upon which the arm may rest, a supportslidably and rotatably mounted on the arm, yieldable means for yieldablyresisting sliding movement or the support, an arbor carried by thesupport, a clamp carried bt the support, the two arbors being so relatedthat a substantially straight length of stock may be positioned adjacentthe same with the arbors on opposite sides thereof, means for anchoringthe stock downstream from the fixed arbor, the clamp being applicable tothe stock upstream from the arbor on the arm, means for swinging the armto cause the stock to be bent about the two arbors with the supportshifting against the yieldable means to accommodate for the take-up ofstock as it is bent about the arbors, a projection on the support, andan inclined surface engageable by the projection substantially at theend of the swinging movement of the arm to shift the support on the armtoward the fixed arbor to thereby loosen the formed bends on the arborsfor removal of the same therefrom.

11. An apparatus for shaping stock of elongated form, such as tube, intocoils of serpentine form having a succession of reverse bends,comprising a fixed arbor, a pivotally mounted arm having its pivotadjacent the fixed arbor, an arbor and clamp unit slidably mounted onthe arm, yieldable means acting upon the unit, a stop for determiningthe rest position of the arm, said arbors being so related that asubstantially straight piece of stock may be positioned adjacent thearbors with the arbors on opposite sides of the stock, means foranchoring the stock downstream from the fixed arbor, said clamp beingapplicable to the stock upstream from the arbor on the arm, means forswinging the arm about its pivot to bend the stock about both arbors,the yielding means serving for movement of the arbor and clamp unit onthe arm to accommodate the take-up of stock as the same is formed aboutthe arbors, whereby said unit moves in a path having a form of aninvolute curve, and means for shifting the arbor and clamp unitsubstantially at the end of the movement of the arm for loosening thebends on the arbors whereby the same may be removed therefrom.

ARTHUR W. PAYNE.

REFERENCES CITED The following references are of record in the file oithis patent:

UNITED STATES PATENTS Number Name Date 1,901,244 Brown Aug. 22, 19111,125,241 Wilson Jan. 19, 1915 1,695,836 Witmer Dec. 18, 1928 1,791,620Hibbard Feb. 10, 1931 2,086,736 Palmer July 13, 1937 2,331,294 Bank Oct.12, 1943

